A fuel-air mixture, assumed equivalent to air, enters a duct combustion chamber at V1 = 104 m/s

Question:

A fuel-air mixture, assumed equivalent to air, enters a duct combustion chamber at V1 = 104 m/s and T1 = 300 K. What amount of heat addition in kJ/kg will cause the exit flow to be choked? What will be the exit Mach number and temperature if 504 kJ/kg is added during combustion?